Electropneumatic signal device



' Feb. 27, 1940. R. RSTEVE'NS ,1 825 ELECTROPNEUMATIC SIGNAL DEVICE Filed Jan. 6. 19:57

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l 6 30 as 42 a z I a I w' l H 2 a ll I INVENTOR ROY RSTEVENS ATTORNEY I Patented Feb. 27, 1940 PATENT cries ELECTROPNEUMATIC SIGNAL DEVICE Roy B. Stevens, Forest Hills, Pa., assignor to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application January 6, 1937, Serial No. 119,198

3 Claims.

This invention relates to sound-producing devices. and more particularly to the type having a vibratory element adapted to be operated by gaseous fluid under pressure, and the principal object of the invention is to provide an improved sound producing device of this type.

In the accompanying drawing Fig. 1 is a diagrammatic, sectional view of a sound producing device embodying the invention; and Fig. 2 is a partial, sectional view taken on the line 22 in Fig. 1-.

As shown in the drawing, the sound-producing device comprises two casing sections I and 2 secured together by screws 3 and cooperating to form a chamber 4 which is connected to a pipe 5 through which fluid under pressure from any suitable source is adapted to be constantly supplied to said chamber.

A frustro-conical shaped casingsection, 6 is sescrews 8, and interposed and clamped between the flange 1 and the periphery of the casing section 6 is a flexible, preferably metallic, vibratory diaphragm 9 and a clamping ring ID, the diaphragm 9 being interposed between the flange I and ring In. I

The diaphragm 9 is provided centrally with an aperture ll extending through a preferably integrally formed, outwardly extending tube 12 the end portion 13, of which is flared. A cone shaped vibratory element l4 made of any suitable material such as relatively stiff paper, is disposed in the flared casing section 6 with the small end secured to the end portion l3 of the tube l2 in any suitable manner, as by rivets l5. larger, open end of the cone shaped element I4 is secured, preferably by rivets It, to a flexible ring I! made of any suitable material such as a f rubber composition. The outer portionof this 40 ring 11 is clamped against a peripheral'flange 7 l8 formed on the casing section 6, by a clamping,

ring I9 secured to flange l8 bybolts 29. The space around the exterior of the cone element I4 and at the right hand side of the diaphragm 9 4.5

apertures 41.

A convex screen 53 made of a closely woven clamping ring l9.

55 A horse-shoe type electro-magnet is disposed in chamber 4 and is secured to and insulated from suitable brackets 2! which in turn are secured to the casing section 2/ This electro-,

magnet comprises a U-shaped core 22, a magnet coil 23 mounted on one leg of said core and cured to a flange l on the casing section-2 by The.

is open to the atmosphere through a plurality of" a magnet coil 24 mounted on the other leg'of 28. A valve seat 2Q adapted to be engaged byv the valve 28 is provided in the end wall 58 of the casing section 2, around a port 5! which leads to a chamber 52 provided at the left hand side. of the diaphragm 9.

A spring 33 is provided for urging the valve 28 into engagement with its seat 29 in which position the armature is spaced from the ends of the armaturecore 22. This spring is disposed in the space between the magnet coils 23 and 24 and is interposed between one side of the armature 2B and an adjusting nuttll mounted on and having screw threaded engagement with an adjusting screw 3!. A pin 32 extends from one side of the nut 30 into a groove 33' provided inthe casing section to prevent said nut from turning and said pin is adapted to slide in said groove to permitmovement of the nut on the adjusting screw.

The adjusting screw 3| has a collar 34 engaging the inner. surface of the end wall of easing section l and extending from said collar through a suitable bore in. said end Wall. to the outside of the casing is a journal portion 35 having in its end a slot 35 through the medium of which the screw may be turned by a screw-driver for adjusting the position of the nut 35 on the screw and thereby adjusting the pressure of the spring 33 on the arrnature'ZB. The opposite end of the screw 3! is reduced in section and is slidably mounted in a suitable bore provided in the armature 26.

Two substantially rigid contact fingers 37 and 38 are secured to and suitably insulated from the casing section 2 within the chamber l, one at either side of the valve 26 and with the end of the fingers arranged to engage the armature 26 when the valve 23 is seated.

The contact finger 3'5 is connected by a wireill to a terminal post M mounted in and insulated from the casing. section 2. The contact finger 38 is connected by a wire ll to one terminal of magnet coil 24' which is connected by wire 42 in series with magnet coil 23, which is in turn connected by a wire 33 to a terminal post at mounted in and suitably-insulated from the casing section 2.

The'terminal post 44 may be connected to any suitable source of electric current such as one L terminal 01' a battery 45. The other terminal of the battery may be connected to one contact of a switch device 46 the other contact of which is connected to the terminal post 40.

In operation, when the switch device 46 is closed the battery 45 is connected in series with the serially connected magnet coils 24, 23 by way of terminal post 40, wire 39, finger 31, armature 26, finger 38, wire 4|, magnet coil 24, wire 42, magnet coil 23, wire 43 and terminal post 44. The magnets 24 and 23 are thus energized and the armature 2B is pulled towards the ends of the core 22 against the opposing pressure of spring 33 and out of engagement with the contact fingers 3! and 38. This opens the circuit through the magnet coils 24' and 23 resulting in deenergization of the magnets which permits spring 33 to urge the armature 26 back into engagement with contact fingers 31 and 38 reestablishing the electric circuit through the magnet coils 23 and 24. The magnet is thus again energized and the armature 26 is again pulled out of engagement with the contact fingers 31 and 38 following which the above operation is repeated. In this manner the armature 26 is caused to vibrate and since the valve 28 is a part of and moves with said armature, said valve is alternately pulled away from its seat 29 by the magnet and urged to its seat by the spring 33, or in other words is caused to vibrate with the armature 26 and permit an intermittent or rapidly recurring series of puffs of fluid under pressure to fiow from chamber 4 into chamber 52.

When the valve 28 is opened, the puff of fluid under pressure supplied to chamber 52 causes a slight increase in pressure therein which acts on the diaphragm 9 to cause it and the cone element M to move outwardly. When the valve 28 seats and cuts ofi the fiow of fluid under pressure into chamber 52, the pressure therein acting on the diaphragm 9 reduces through the aperture ll in tube l2 and permits the diaphragm 9 and cone element l4 to move toward the left hand. Aided by the resilience of the diaphragm 9' and cone element M, said diaphragm and cone element are thus caused to vibrate at the same rate as the valve 28 is opened and closed and this causes the body of air in the cone element to be maintained in a state of vibration thereby producing sound vibrations.

The pitch of the tone produced by the vibration of the diaphragm 9 and cone element l4 depends upon the rate of vibration of the valve 28 relative to its seat 29 and may be varied by varying the pressure of spring 33 on the armature 26. The pressure of the spring 33 is varied by turning the adjusting screw 3 l through the medium of which the adjusting nut 30 may be moved either towards or away from the armature 26, as desired,

When it is desired to prevent further sounding of the signal device, the switch device 46 is opened thus cutting oiT the supply of electric current to the magnet devices. The spring 33 then acts to hold the valve 28 seated to prevent flow of fluid 'under pressure from chamber 4 to chamber and electro-magnetic means for effecting the operation of the Valve to provide a recurring series of puffs of fluid under pressure to act on a vi-' bratory element for effecting its operation to produce sound vibrations.

vention has been described in detail, it is not my intention to limit its scope to that embodiment a or otherwise than by the terms of the appended claims.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is: I

1. A sound producing device comprising a vibratory diaphragm having at one side a chamber and adapted to be vibrated by successive increases in fluid pressure in said chamber, a source of gaseous fluid under pressure, valve means controlling a communication through which fluid under pressure is adapted to be supplied from said source to said chamber, electromagnetic means operative upon energization' to effect movement of said valve means to a position for opening said communication and upon deener-v gization to effect movement of said valve means to another position for closing said communication, and means operative in one position of said valve means to effect energization' of said electro-magnetic means and in the other position to efiect deenergization of said electr'o-magnetic means, said diaphragm having an aperture con-f necting said chamber to the atmosphere at the opposite side thereof, said aperture having '-a flow capacity so related to that of said communi cation as to cause a differential of fiuid pressures: to be established on said diaphragm when said communication is open. I 1

2. A sound producing device comprising a cas-' ing having a chamber supplied with gaseous fiui d magnet and upon de'energizationof saidmagnet to efiect energization of said magnet, said device having means for releasing the fluid pressure? supplied to said one face of said diaphragm at a rate'less than the rate of supply through said communication when open.

3. A gaseous operated sound producing device comprising a vibratory diaphragm having at one side a chamber and having an aperture exten'df ing axially through the diaphragm, a conical vi" bratory element having its smaller end securedto said diaphragm around said aperture, flexible means'carrying the larger open end of said conical element, a source of fluid pressure, a valve for opening a communication between said source and chamber having a flow capacity suinciently in excess of said aperture to provide a difierential; of fiuid pressures on said diaphragm for movingsaid diaphragm and element in one direction, saiddiaphragm and element being movablein the op posite direction upon closure of said valve and equalization-of the fluid pressureson said diaphragm, and means for vibrating said valve to: open and close said communication and for, thereby efiecting variations in fiuid pressure in] said chamber to effect vibration of said diaphragm and element. p, v

ROY R. STEVENS." 

